Starch for cancer prevention?Not as banana as I expected

A long-term follow-up study of the randomized CAPP2 trial showed that resistant starch had a protective effect against nonpolypto-rectal Lynch syndrome-related cancers.

After up to 20 years of follow-up, 5.8% of participants randomized to resistant starch (a component of dietary fiber in foods such as bananas, potatoes, grains, legumes, and seeds) have non-colorectal Lynch syndrome. Cancer Compared 10.5% of participants were randomized to placebo by ITT (intention-to-treat) analysis (HR 0.54, 95% CI 0.33-0.86, P= 0.010), reported by Dr. John Mothers and his colleagues at Newcastle University in Newcastle upon Tyne, England.

This effect was even greater in a protocol-specific analysis limited to participants who had been treated for more than 2 years (HR 0.42, 95% CI 0.22-0.81,). P= 0.0090), they Cancer prevention research.

The protective effect of resistant starch against cancer of nonpolypical Lynch syndrome was evident in both ITT (incidence ratio). [IRR] 0.52, 95% CI 0.32-0.84, P= 0.0075) and per protocol (IRR 0.37, 95% CI 0.19-0.73, P= 0.0040) Analysis. The effect was particularly pronounced in upper gastrointestinal cancer (stomach cancer, duodenal cancer, biliary tract cancer, pancreatic cancer, etc.), 5 in the resistant starch randomized and 21 in the placebo group. ..

Mathers et al. Called this finding “unexpected” and, with important implications, “surveillance of such cancers is difficult and the post-diagnosis survival rate of upper gastrointestinal cancer is that of other Lynch syndromes. It’s much lower than cancer. “

In particular, there was no difference in the incidence of colorectal cancer between groups (CRC; 52 patients with resistant starch vs. 53 with placebo).

“This limited-term indigestible starch dietary supplement does not embody the apparent protective effect of a fiber-rich diet against CRC in the general population,” Mathers and the team observed.

CAPP2 was also designed to investigate the long-term effects of aspirin, including resistant starch, on cancer incidence in patients with Lynch syndrome. Mathers et al. Found that there was no interaction between aspirin and resistant starch treatment.

An early analysis of the study was conducted in patients with Lynch syndrome who received aspirin. Significantly reduced risk of developing CRC Compared to placebo (HR 0.65, 95% CI 0.43-0.97, P= 0.035 in ITT analysis). Another previous analysis of CAPP2, based on an interim follow-up with a median of 52.7 months, found that: Resistant starch had no detectable effect Incidence of CRC in these patients-findings consistent with the results of current studies.

Given that resistant starch does not appear to reduce the risk of CRC in patients with Lynch syndrome, what explains the apparent protective effect against other cancers?

“Resistant starch is a type of carbohydrate that is not digested in the small intestine. Instead, it ferments in the large intestine and nourishes beneficial gut bacteria,” Mothers said in a press release. “It works as effectively as your digestive fiber. This type of starch has some health benefits and has fewer calories than regular starch. Tolerant starch is bile acid. I think we can reduce the incidence of cancer and reduce their types by altering the bacterial metabolism of the bile acid, which can damage our DNA and ultimately cause cancer. “

“But this requires more research,” he added.

Since 1999, researchers have recruited 937 patients with Lynch Syndrome (mean age 45 years). In the 2×2 factor experiment, participants received 600 mg of enteric-coated aspirin or placebo and 30 g of resistant starch or placebo daily. The main hypothesis of CAPP2 was that each intervention individually prevented CRC. The secondary result was the effect of each intervention on non-CRC cancers.

Participants came from 43 international centers (82% from Europe and the rest from Australia, Africa and the Americas). The current analysis included 10 years of data across all centers, as well as up to 10 years of registry follow-up for participants from England, Wales, and Finland.

Mathers et al. Acknowledged that the potential weakness of this study was that the original hypothesis focused on CRC.

“It’s surprising, but not impossible, to detect the effects of other Lynch syndromes on cancer long after a relatively short intervention,” they write. “”[M]Utagens can damage stem cells and cause malignant tumors years later. This is especially true if the DNA repair mechanism is compromised. “